Apparatus for severing a sheet

ABSTRACT

Apparatus for severing a sheet of material such as photographic film or paper, comprising a plane table having a cutting edge; a knife movable into and out of shearing relationship with the cutting edge; a shaft supporting the knife and having a longitudinal axis spaced ahead of the cutting edge outboard thereof, the knife being pivotally movable about said axis; and levers for supporting the shaft for movement in an arc about a pivot. A spring urges the knife inwardly toward the cutting edge, and also acts to restore the knife to its initial position after each cutting operation. Advantageously the spacing of the shaft ahead of the cutting edge is such that a first plane through the shaft axis and a line along the cutting edge forms an acute angle of 10*-15* with a second plane through said line and normal to the plane table. The principles apply to cuts straight across a sheet, and to oblique cuts (in the latter case, said line extends across a terminal point of the knife edge).

United States Patent Symonds [4 1 June 27, 1972 [54] APPARATUS FORSEVERING A SHEET [72] Inventor: Willard G. Symonds, Rochester, NY.

[73] Assignee: Eastman Kodak Company, Rochester,

[22] Filed: Nov. 18, 1970 [21] Appl. No.: 90,501

[51] Int. Cl ..B26d 5/10 [58] Field ofSearch ..83/582,633,634, 636, 600,83/610-612 [56] References Cited UNITED STATES PATENTS 1,952,961 3/1934Yates ..83/611 2,623,589 12/1952 Price.... .....83/1l0 947,744 l/19l0Stohr ..83/371 1,565,654 12/1925 Laukhuff.... ....83/582 X 3,376,7754/1968 Eliason ..83/582 Primary Examiner-Donald G. Kelly Attorney-WalterO. Hodsdon and Henry M. Chapin [5 7] ABSTRACT Apparatus for severing asheet of material such as photographic film or paper, comprising a planetable having a cutting edge; a knife movable into and out of shearingrelationship with the cutting edge; a shaft supporting the knife andhaving a longitudinal axis spaced ahead of the cutting edge outboardthereof, the knife being pivotally movable about said axis; and leversfor supporting the shaft for movement in an are about a pivot. A springurges the knife inwardly toward the cutting edge, and also acts torestore the knife to its initial position after each cutting operation.Advantageously the spacing of the shaft ahead of the cutting edge issuch that a first plane through the shaft axis and a line along thecutting edge forms an acute angle of l0-l5 with a second plane throughsaid line and normal to the plane table. The principles apply to cutsstraight across a sheet, and to oblique cuts (in the latter case, saidline extends across a terminal point of the knife edge).

11 Claims, 4 Drawing Figures PATENTEDJURN in SHEET 2 OF 2 F IG. 4

APPARATUS FOR SEVERING A SHEET BACKGROUND OF THE INVENTION 1. Field ofthe Invention My invention relates to novel apparatus for severing asheet of material, and more particularly to such apparatus that issimple and inexpensive in construction and which is particularly usefulfor shearing long photographic film and paper into shorter lengths.

2. Prior Art Shearing apparatus for this purpose has been known foryears but is more complicated and expensive in construction than isdesirable, andrequires frequent sharpening. Moreover, difficulty hasbeen encountered with prior devices in shearing tough materials such aspoly(ethylene terephthalate) photographic film bases of variousthicknesses. When such apparatus is preset for shearing one thickness ofsuch polyester sheet, it will not shear thicker sheets. It will shearthinner sheets, but the wear on the blades is then excessive, andfrequent resharpening is necessary.

THE DRAWINGS FIG. 1 is a perspective view of one embodiment of my noveldevice for cutting straight across a sheet;

FIG. 2 is an elevational view of my novel device as viewed from the rearof FIG. 1;

FIG. 3 is a side elevational view of my device as seen from the right inFIG. 1, and from the left in FIG. 2; and

FIG. 4 is a schematic plan view showing my apparatus as designed to cutan arrow or fish tail shape in a sheet.

SUMMARY OF THE INVENTION In general my novel apparatus for severing aweb or sheet of material comprises a plane table T for supporting theweb, having one edge E acting as a cutting edge for receiving'the web inposition to be severed. Edge E is stationary during a cutting operation,but in some instances it may be made adjustable for presetting theapparatus; A knife K, having a cutting edge which is inclined withrespect to edge E, is movable into and out of shearing relationship withthe cutting edge. Knife K is supported by a shaft S having alongitudinal axis which is spaced ahead of the cutting edge outboardthereof. The arrangement is such that when shaft S is parallel to thecutting edge E, a first plane through both the cutting edge and thelongitudinal axis of shaft S forms an acute angle A of at least(advantageously 10-I5") with a second plane passing through the cuttingedge and normal to table T. Moreover knife K is pivotably movable aboutthe longitudinal axis of its shaft 8 during shearing movement. When theap paratus is adjusted for proper cutting, shaft S usually is notabsolutely parallel to edge E, but is essentially parallel, with aslight angularity thereto which may be 0.001 to 0.005 inch per inch oflength. This angularity is well known as crossover" in this art, and theterm essentially parallel as used herein is intended to encompass such aslight departure from absolute parallelism.

A coil spring C resiliently urges the knife K in two directions, intoward the cutting edge E and up toward a reset position to which theknife returns after each cut.

The principles of construction described generally above are applicableto a wide range of sizes and shapes of apparatus, depending on theparticular needs. They have been applied to devices for chopping 16 mmwide photographic film, and to devices for chopping film as wide as 6and 12 inches and more. Moreover, the principles are universallyapplicable to various materials and thicknesses, being useful on webs ofphotographic paper, cellulose acetate film base, and tough poly(ethyleneterephthalate) film base.

The apparatus can be operated with table T horizontal as shown, ortilted, or even inverted.

THE SPECIFIC EMBODIMENT In the specific apparatus shown in FIGS. 1-3 forillustrating the principles of my invention, table T is securely boltedat its sides to two upstanding frame members 11 and 13 which are joinedon their tops by a cross bar 15.

Knife K is supported on shaft S by a pair of brackets 17 and 19 havingbores fitting over shaft S, with the brackets being fixed by set screwsto the shaft which itself is rotatably mounted at its ends in boreswhich extend through front end portions of two parallel lever arms 21and 23. Alternatively, for greater strength, the ends of shaft S can befixed by set screws rigidly to the lever arms, and the brackets can berotatable on the shaft.

Adjacent their rear ends the arms 21 and 23 have bores through which asecond shaft 25 passes and has its ends extending into, and rotatablein, bores in a pair of blocks 27 and 29 which are adjustably bolted tothe inside surfaces of frame members 11 and 13 by bolts 28 and 30located off center of the blocks. Shaft25 acts as a pivot for the leverarms to permit knife K-to be moved up and down. Arms 21 and 23 arestaked or otherwise fixed to shaft 25 to rotate therewith.

For moving knife K up and down there is provided still another lever arm31 which is located centrally on, and has bores receiving, shafts S and25. Lever arm 31 projects forward of shaft S for manual actuation, orfor engagement with a plunger or other actuating mechanism. Lever arm 31is fixed by a set screw or other device to shaft 25, but is not fixed toshaft S which can rotate therein. Alternatively, actuating force can beapplied to lever arms 21 and/or 23 at points between shafts S and 25.

An adjustable stop bolt 35 extends through cross bar 15 to engage leverarm 23 at its uppermost position so as to assure the end portion 37 ofknife K remains in position adjacent to cutting edge E upon thecompletion of each cut. In addition, a set screw 38 projects down fromarm 23 in position to engage the top edge 40 of knife K to prevent thebottom edge of the knife from overlapping the table T and preventing thenext downward movement of the knife. Return of knife K to its initialposition and proper positioning of knife portion 37 are assured by coilspring C which is mounted at one end over an adjustable bolt 39projecting forwardly from cross bar 15, and at the opposite end extendsthrough a bore in knife K. The angular relationships are shown clearlyin FIG. 3, being such that the spring urges the knife K both upwardlyaway from table T, and in toward cutting edge E.

As pointed out above, the longitudinal axis of shaft 25 and the cuttingedge E are essentially or substantially parallel although a slightcrossover" angularity is desirable. The amount of angularity can beadjusted by loosening one or both of bolts 28 and 30, whereupon theblocks 27 and/or 29 can be swung eccentrically around the bolts to theslight extent required.

Spring C is important for bringing end portion 37 of the knife from aposition slightly above and in front of edge E down and rearwardly intocontact with edge E at the start of the cutting operation, but once theout has started at one end of knife K it will proceed completely acrossthe knife without further need for spring pressure. As a practicalmatter, however, the spring is continuously operative both for startingthe cutting operation and for resetting the knife K after each cut.

It is evident that spring C can be located close to either end of knifeK rather than near the center. Also, for heavy cutting of wide sheets aplurality of springs can be used, for example two located near the endsof the knife.

My principles apply also to the cutting of a sheet with a shape otherthan straight across the sheet, for example one or more oblique cuts,such as the arrow-shaped or fish tailshaped cut shown in FIG. 4schematically. A shaft S carrying an appropriately shaped shearing knifeK again has its axis spaced in front of an appropriately shaped cuttingedge E on the end of a plane table T. Here the angular relationship of10-l5 is defined between (a) a first plane which passes through bothaxis S and a line L which is essentially parallel thereto and extendsacross the foremost or leading corner or corners of edge E, and (b) asecond plane which includes line L and is normal to table T.

The two modifications of apparatus described in detail above have beenfound particularly advantageous for cutting tough polyester sheets ofvarious thicknesses, and without requiring frequent resharpening.Cutters available previously had to be especially designed and set forone specific thickness, and would not operate successfully on thickermaterial. Previous cutters would operate successfully on thinner sheets,but then excessive wear on the knife edges occurred and they had to beresharpened too frequently.

My improvements can be ascribed mainly to the automatic self loading ofthe knife blade against the knife edge of the cutting table, resultingfrom the described positioning of shafts S and S, and the describedangular relationship, taken together with the spring for assuring theinitial correct positioning of the knife and its return to position uponcompletion of a cutting operation.

Furthermore, my apparatus is simple and inexpensive to construct, and isuniversally adaptable to the cutting of various sheet materials such aspaper, cellulose acetate film, and polyester film.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

I claim:

1. In apparatus for severing a sheet of material, comprising incombination,

a horizontal table lying in a reference plane for supporting said sheet,one edge of said table forming a stationary cutting edge lying in aplane normal to said table for receiving said sheet in position to besevered, a knife movable from an initial position into and out ofshearing relationship with said cutting edge, a first shaft supportingsaid knife and having a longitudinal axis laterally spaced from saidnormal plane, and lever means for supporting said first shaft formovement in an arc about a pivot, the improvement wherein:

said knife is pivotally movable about said longitudinal axis of saidfirst shaft and biased by resilient means into engagement with saidcutting edge.

2. In apparatus in accordance with claim 1, wherein said resilient meanscomprises a spring for urging said knife into contact with said cuttingedge during cutting movement thereof.

3. In apparatus in accordance with claim 2, said last named meanscomprising a resilient spring mechanism acting both to urge said knifeinto contact with said cutting edge and to resiliently urge said knifeand said shaft in a direction out of shearing relationship with saidcutting edge to restore said knife to the initial position thereof aftercompletion of a severing operation.

4. In apparatus in accordance with claim 1, said knife being fixed tosaid shaft, and said shafl being joumalled for rotation in said levermeans.

5. In apparatus in accordance with claim 1,

support means projecting from said table normal thereto,

said lever means comprising a second shaft spaced rearwardly from saidfirst shaft and mounted in said support means to act as said pivot.

6. In apparatus in accordance with claim 5, wherein said resilient meanscomprises a resilient spring mechanism urging said knife into contactwith said cutting edge during cutting movement thereof, said springmechanism extending between said support means and said knife and alsoacting to urge said knife in a direction out of shearing contact withsaid cutting edge to restore said knife to the initial position thereofafter a severing operation.

7. In apparatus in accordance with claim 6, adjustable stop means forlimiting the upward movement of said knife and for limiting the pivotingmovement of said knife on said first shaft in the direction of saidcutting edge upon restoration of said knife to said initial position.

8. In apparatus in accordance with claim 1 said shaft being sopositioned that a first plane extending through the longitudinal axis ofsaid shaft and also through said cutting edge, forms an acute angle ofat least 10 with said normal plane. 9. An apparatus in accordance withclaim 8, said acute angle being between 10 and 15.

10. In apparatus in accordance with claim 1, said cutting edge beingstraight and essentially parallel to said axis.

11. In apparatus in accordance with claim 1, said cutting edge beingnon-parallel to said axis.

'ggg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,672 \252 Dated June 27L 1972 lnventor(s) Willard G. Svmonds It iscertified-that error appears in the above-identified patent that saidLetters Patent are hereby corrected as shown below:

and

Column 3, line 32, delete "horizontal".

Signed and sealed this ZL tb day of October 1972.

(SEAL) Attest:

EDWARD M.FLETC IHER,JR. ROBERT GOTI'SCHALK 'Attestung OfflCGl"Commissioner of Patents

1. In apparatus for severing a sheet of material, comprising incombination, a horizontal table lying in a reference plane forsupporting said sheet, one edge of said table forming a stationarycutting edge lying in a plane normal to said table for receiving saidsheet in position to be severed, a knife movable from an initialposition into and out of shearing relationship with said cutting edge, afirst shaft supporting said knife and having a longitudinal axislaterally spaced from said normal plane, and lever means for supportingsaid first shaft for movement in an arc about a pivot, the improvementwherein: said knife is pivotally movable about said longitudinal axis ofsaid first shaft and biased by resilient means into engagement with saidcutting edge.
 2. In apparatus in accordance with claim 1, wherein saidresilient means comprises a spring for urging said knife into contactwith said cutting edge during cutting movement thereof.
 3. In apparatusin accordance with claim 2, said last named means comprising a resilientspring mechanism acting both to urge said knife into contact with saidcutting edge and to resiliently urge said knife and said shaft in adirection out of shearing relationship with said cutting edge to restoresaid knife to the initial position thereof after completion of asevering operation.
 4. In apparatus in accordance with claim 1, saidknife being fixed to said shaft, and said shaft being journalled forrotation in said lever means.
 5. In apparatus in accordance with claim1, support means projecting from said table normal thereto, said levermeans comprising a second shaft spaced rearwardly from said first shaftand mounted in said support means to act as said pivot.
 6. In apparatusin accordance with claim 5, wherein said resilient means comprises aresilient spring mechanism urging said knife into contact with saidcutting edge during cutting movement thereof, said spring mechanismextending between said support means and said knife and also acting tourge said knife in a direction out of shearing contact with said cuttingedge to restore said knife to the initial position thereof after asevering operation.
 7. In apparatus in accordance with claim 6,adjustable stop means for limiting the upward movement of said knife andfor limiting the pivoting movement of said knife on said first shaft inthe direction of said cutting edge upon restoration of said knife tosaid initial position.
 8. In apparatus in accordance with claim 1, saidshaft being so positioned that a first plane extending through thelongitudinal axis of said shaft and also through said cutting edge,forms an acute angle of at least 10* with said normal plane.
 9. Anapparatus in accordance with claim 8, said acute angle being between 10*and 15*.
 10. In apparatus in accordance with claim 1, said cutting edgebeing straight and essentially parallel to said axis.
 11. In apparatusin accordance with claim 1, said cutting edge being non-parallel to saidaxis.